Shedding light on dark DNA Most textbook definitions of evolution state that it occurs in two stages: mutation followed by natural selection. DNA mutation is a common and continuous process, and occurs completely at random.
The average adult only eats 15 grams of fiber per day. Women need 25 grams of fiber per day, and men need 38 grams per day, according to the Institute of Medicine.
These total fiber requirements provided by the Institute of Medicine are 21 grams per day for women ages 50 and older, 25 grams for women younger than age 51, 30 grams for men ages 50 and older and 38 grams of total fiber per day for men younger than age 51.lthough your daily fiber requirements are based on grams of total fiber, getting recommended amounts of soluble fiber each day can help prevent, or reduce the severity, of certain health conditions.